Hi guys,

I will start to build my HT very soon (currently in the never ending design phase) and one of the thing I can't make a decision on is how much I need to do on soundproofing. I've read all the articles on soundproofingcompany.com and numerous posts on AVS forums, so I am aware of the "ideal" setup. Unfortunately for a few reasons, that ideal setup is impossible for me. I am debating the overall benefit versus cost of using clips.

What I know is the ceiling and the interior walls (outside walls are concrete walls, so they'll receive a single drywall sheet) will be GG + 2x 5/8 drywall, no staggered studs. Walls and ceiling will be filled with R13 insulation. I know that if I use RSIC clips with hat channels, it will be better... But how much better? I live in Canada and finding good hat channels is tough. The use of clips will also lower my ceiling. I am not looking for the perfect room, but I want to build something decent. Sometimes a 85% solution will do the job since getting that remaining 15% is too expensive or involves too many constraints. Is it the case of RSIC clips?

Thanks a lot guys.

I too went for the 85% solution. I wish I was done and could share results but am not there yet.

See the reedzone thread for a way to reduce the ceiling height issue. I used the same technique.
http://www.avsforum.com/avs-vb/showpost.php?p=8633279&postcount=9

If cost is an issue, as it was for me, then consider RSIC-V on the ceiling using the technique outlined in the reedzone thread.

For the interior walls, staggered studs can be done by reusing the existing wall, widening the top and bottom plates (say, by ripping 2x4) and then adding new studs in between the existing but attached to top and bottom plates lined up with the widened part. This should be easy and no more than $50 per wall.

If you are going to do an 85% solution - do it smartly IMHO.

On green glue - you are building an aquarium and you want all the walls to perform. If you do it halfway you will have walls that have differing isolation value, and thus create flanking paths. Your chain is only as strong as the weakest link.

IMHO - the single undamped layer drywall on certain walls but not on others is the wrong way to go. I am speculating that SQ FT and cost of GG are the issues. If thats the case, you will have better walls with 2 layers of 1/2" drywall with 50% coverage of GG all around then selectively doubling up and damping. Did you know that you get 70% of the GG benefit at 50% coverage? Also, you are better served having the mass of 2 layers of 1/2 than selective layers of 5/8ths (although I'd use 5/8ths if you can spare the extra space - why sell short on a small interval).

Also, IMHO, if you can spare an inch on the interior walls, and do the ceiling maxing clip install then you are adding decoupling to your build, which will aid you.

Thanks for the link D-train. I will look into this for sure.

dc_pilgrim, I guess when you say 50% coverage of GG, you mean only one tube per sheet instead of 2?

Thanks a lot guys.

To re-cap the good thoughts expressed here, double up drywal on the side walls next to the foundation. Otherwise sound will simply go through the single layer drywall and up into your joists.

You want decoupling on all walls and ceiling. It's too easy and cheap relative to the large isolation gains at this point

The single stud walls are about as expensive as a staggered wall. Build them 24" on center to conserve cost. A single stud wall you'll regret later. Staggered studs next to other rooms, and a single stud wall 1" away from the foundation. All decoupled now.

Use an inexpensive 1 piece clip on the ceiling to decouple, then double drywall.

Use 1 tube per sheet of GG if the total cost is an issue. You'll get 70% of the benefit

To re-cap the good thoughts expressed here, double up drywal on the side walls next to the foundation. Otherwise sound will simply go through the single layer drywall and up into your joists.


Ted,

If the entire ceiling has RSIC clips, GG and 2 layers of 5/8" drywall, wouldn't it be OK to have foam, 2x2" studs and a single layer of drywall next to the foundation? My simple thinking is that the sound would already be prevented from going up to the rooms on the floor above. So even if it went through the one layer, it would still have to travel above. Thanks.

What happens when sound passes through that single layer of drywall? Where can it go? Straight up into your joists

But when it goes up - doesn't it run into two layers of drywall?

My thoughts are to install the ceiling first. See this primitive diagram and actual photo. Thanks for sticking with me on this.

http://www.cinemarsolutions.com/cinemartheater/images/ceiling_diagram.jpg

http://www.cinemarsolutions.com/cinemartheater/images/ceiling_photo.jpg

Ladoe00: Hey .. a fellow Ottawan. Welcome to the madness.

For the hat channel, I found this place:

http://www.gratienproulx.com/index_eng.htm

Might want to check them out.

Send me a PM if you want.

Mario, regarding your diagrams and plan to drywall the ceiling first and then build the side walls under the drywall as a strategy for containing flanking sound:

How would you plan to attach the top plate of the 2x2 side walls, Just to the drywall? not a good idea, Screw through the drywall to hit the joists? not a good idea it would decouple your assembly.

So what you would need to do is mount the wall framing to the concrete walls with RSIC clips and make sure that the framing is built just shy of touching the drywall ceiling. You need to consider that all those attachment points would provide a break in the insulation/vapor barrier.

I also pity the next guy would would come along and want to do some remodeling.

I'm sure Ted will chime in, but this thread contains similar info from when I was asking some of these same questions.

http://www.avsforum.com/avs-vb/showthread.php?t=1032371&highlight=